Effect Of The Structure Of Reclaiming Agent To The Struchture And The Property Of Reclaimed Rubber

Three kinds of amine used as reclaiming agent were studied in this paper. They areOctadecylamine, Methenamine and Tetraethylenepentamine. The reclaimed rubberdevulcanized with variation of the concentration of the reclaiming agents, the reclamationtemperature and time was researched, and the optimum reclamation condition wasdetermined by these experiments. The comparative study of the three kinds of reclaimedrubber devulcanized with different reclamation condition shows the relationship betweenthe structure and the structure and properties of the reclaimed rubber.The study of Octadecylamine show that Octadecylamine is useless when thereclamation temperature is less than170℃,The crosslinking density and the Mooneyviscosity decrease with increasing reclamation temperature.There is a maximum of tensilestrength and elongation at break when the reclamation temperature is190℃;Thecrosslinking density and Mooney viscosity decrease when the concentration ofOctadecylamine change from0to0.5wt%,and increase with the continue increasing ofconcentration,The tensile strength and elongation at break first increased and thendecreased with the increasing of concentration, these results indicate that Octadecylamineact as reclaiming agent and accelerant,devulcanizaton is the main function in lowconcentration and sulfuration is more and more obvious with the concentration increasing;The increase of reclamation time cause the decrease of the crosslinking density and theMooney viscosity, elongation at break have the opposite tendency,and tensile strengthfirst increased and then slightly decreased. The result is that190℃is the optimumreclamation temperature,1.5wt%is the optimum concentration and12.5min is the optimum reclamation time.The result of the research to Methenamine indicate that the crosslinking density andMooney viscosity decrease and tensile strength and elongation at break increase with theincreasing of reclamation temperature;An increase of the concentration of Methenaminefrom0to0.5wt%results in the increase of crosslinking density and Mooney viscosity,however, the crosslinking density and the Mooney viscosity decrease with the continueincrease of the concentration of Methenamine, the elongation at break decrease and thetensile strength have little change with the increase of the concentration of Methenamine,the conclusion is that Methenamine have the opposite function with Octadecylamine; Forthe increasing of reclamation time,the crosslinking density, Mooney viscosity and tensilestrength reduce, and the elongation at break have a slightly rise. It obvious that thereclaimed rubber have good properties when the reclamation temperature is200℃, theconcentration of Methenamine is1wt%and the reclamation time is15min.When the reclaiming agent is Tetraethylenepentamine,the conclusion is that thecrosslinking density and the Mooney viscosity decrease because of the increasing ofreclamation temperature, tensile strength and elongation at break have the oppositetendency; A long with the increase of the the concentration of Tetraethylenepentamine,thecrosslinking density and the Mooney viscosity first decreased and then increased rapidly,there is a minimum when the concentration is0.5wt%, the tensile strength and theelongation at break increase fast, It is clear that Tetraethylenepentamine have the samefunction with Octadecylamine in devulcanizaton process; For the increasing ofreclamation time, crosslinking density, Mooney viscosity and tensile strength reduce, andelongation at break increase.200℃is the optimum reclamation temperature,0.5wt%isthe optimum concentration and15min is the optimum reclamation time.The comparative study of the three kinds of amine indicate that the reclaimed rubberdevulcanized with Tetraethylenepentamine have the best comprehensive properties, theMooney viscosity (ML(1+4)100℃) is68.4, it means that this rubber have good processability, the tensile strength is16.13MPa and the elongation at break is500.7%, thephysical and mechanical properties is the best in three kinds of reclaimed rubber.